An attacker can create a malicious GIF file which can force the total number of loop cycles to be extremely big
(lile r8d=0x8000000000, 0x100000, ...). This causes the loop to overwrite arbitrary memory data.

In order to trigger this vulnerability the GlobalColorTableFlag from the LOGICALSCREENDESCRIPTOR_PACKEDFIELDS
needs to be 1 and the SizeOfGlobalColorTable needs to be set to 7.

Additionally, the value returned by sub_18000A780 (later used for shif-logical-left operation - CL register (count))
is taken directly from the poc file (offset 0x3f2).